Advancing mechanism

ABSTRACT

The mechanism advances a plate bearing a plurality of objects at regularly spaced positions to bring each object accurately to a predetermined work station. The mechanism is operated by the alternate up and down movements of a distributor or tool. The plate bearing the objects has pegs projecting at positions corresponding respectively to those of the objects. The tool moves alternately from a upper or rest position to a lower or working position. A lever is pivoted on the tool. In the equilibrium position of the lever a first cam surface thereon contacts and pushes forward one peg at a time. A second cam surface on the tool extends the first cam surface and completes the pushing of the plate by one step. The following peg pivots the lever away from its equilibrium position when the tool is returning to its rest position.

O United States Patent 1 1 11 11 3,762,228 Crepin 1 Oct. 2, 1973 ADVANCING MECHANISM Primary ExaminerCharles J. Myhre [75] Inventor. Jean Claude Crepin, Paris, France Assistant Examiner wesley s. Ratliff Jr. [73] Assignee: Choay S.A., Paris, France Att0rneyFleit, Gipple & Jacobson [22] Filed: Oct. 5, 1971 [57] ABSTRACT [21] Appl' l86673 The mechanism advances a plate bearing a plurality of objects at regularly spaced positions to bring each ob- [52] US. Cl 74/128, 74/822, 74/88 ject accurately to a predetermined work station. The [51] Int. Cl. Fl6h 27/02 mechanism is operated by the alternate up and down [58] Field of Search 74/128, 822, 826, movements of a distributor or tool. The plate bearing 74/88, 78, 142, 816, 817 the objects has pegs projecting at positions corresponding respectively to those of the objects. The tool moves [56] References Cited alternately from a upper or rest position to a lower or UNITED STATES PATENTS working position. A lever is pivoted on the tool. In the 2,672,773 3 1954 Schofield 74/822 equilibrium Positim the [ever a first cam Surface 2.780372 2/1957 Covm et aL 74,88 thereon contacts and pushes forward one peg at a time. 2925.052 2 19 0 Glass H 74/128 A second cam surface on the tool extends the first cam 3,021,030 2/1962 Thompson 74/ 128 surface and completes the pushing of the plate by one 3,141,356 7/1964 l-lerbkersman 74/822 step. The following peg pivots the lever away from its J J 11/1964 au 74/88 equilibrium position when the tool is returning to its 3,l6l,070 12/1964 Venables 74/88 rest position 3,220,269 ll/l965 Gennaro 74/88 3,444,747 5/1969 Zeppelin et al 74/88 9 Claims, 4 Drawing Figures ADVANCING MECHANISM The invention relates to an improved mechanism suitable for use in a treatment device, especially for automatic analysis, of a plurality of samples, of the type which comprises, on one hand, a plate on which the samples are capable of being arranged in regular spaced positions so that unitary displacements of this plate enable successive introductions of each of these samples at a given fixed station and, on the other hand, a member denoted below in a general manner under the term of distributor adapted to undergo alternate movements, especially in a vertical direction, between a resting position and a working position, this distributor being adapted, in this latter position, to effect at least one of the treatment operations on that of these samples which occurs at this moment at the abovesaid fixed station.

It relates more particularly to improvements in an advancing mechanism for use in the invention described in Applicants copending patent application Ser. No. 885,662 filed 16 Dec. 1969 patented Nov. 30, 1971, US. Pat. No. 3,623,381.

The treatment device described in the latter application is essentially characterised in that the distributor bears a member capable of cooperating with the plate, so as to make it undergo a unit movement, each time that the distributor is brought from its resting position into its working position, this distributor only being adapted to reach this latter position if the plate has undergone a complete unit movement.

In the device described in the aforesaid application, the alternate displacements of the distributor are effected in a vertical direction, the plate comprises elements projecting at positions respectively corresponding to those of the samples, and the member borne by the distributor comprises a pivoting lever comprising an inclined ramp which, when the distributor is in its resting position, is vertically over one of these projecting elements, this lever being mounted in such manner on the distributor that it rocks from its equilibrium position towards a different position, in the course of effecting the movement of the plate, under the effect of the thrust which is brought to bear on the projecting element concerned, in the course of the descent of the distributor, this rocking being sufficient for this ramp to occur again vertically over the following element when the lever has been brought back into its equilibrium position, on the reascent of the distributor.

It is an object of the invention to provide an improved advancing mechanism, having one or more of the advantages of increased accuracy, speed, control and greater simplicity. Other features and advantages will emerge from the description which follows.

GENERAL ARRANGEMENT The device according to the invention, of which the distributor bears also a pivoting lever itself comprising a cam surface adapted to contact and to push back one of the abovesaid projecting elements of the plate to trigger a unit movement of the latter, when the distributor is displaced towards its working position, is characterised in that the cam surface of this pivoting lever is of a sufficiently reduced length so that it loses contact with the projecting element concerned, before the plate has achieved a unit displacement, that the distributor itself comprises a second cam surface substantially extending and relaying the preceding one at the moment of this loss of contact, to complete the unit displacement of the plate when the distributor pursues its displacement towards its working position, and the pivoting lever is mounted on the distributor so that it is constrained by the following of projecting element the plate, to rock towards a position displaced with respect to its equilibrium position, in the direction of unit displacements of the plate, when the distributor returns to its resting position.

SPECIFIC EMBODIMENTS In a preferred embodiment of the invention, the alternate movements of the distributor are effected in a vertical direction; the plate is circular and comprises pegs on its periphery forming projections; the cam surfaces borne by the pivoting lever and by the distributor respectively are constituted by ramps inclined to the horizontal, the distributor ramp being aligned, at least approximately, with that of the pivoting lever, when the latter is in its equilibrium position, this pivoting lever being finally mounted in such a way on the distributor that it cannot rock as long as its contact with one of the abovesaid pegs persists, in the course of the descent of the distributor.

In order that the invention may be more fully understood, a preferred embodiment of the device according to the invention, is described below purely by way of illustrative but non-limiting example, with reference to the accompanying drawing, in which FIG. 1 shows in perspective a portion of an automatic treatment device for a plurality of samples, incorporating a mechanism according to the invention FIGS. 2, 3 and 4 show an enlarged view in elevation of one of the portions of the embodiment of FIG. 1 in various positions that it is capable of occupying in the course of its operation.

The embodiment described by way of example relates to a device intended to enable automatic chromatographic analyses, especially the automatic introduction of successive samples, for example of aminoacids into chromatographic columns filled with ionexchange resin.

Such a device of course includes a sample support, constituted for example by a circular plate 1 capable of being actuated by unit angular movements around its axis, comprising a series of orifices 2, arranged for example in two concentric circular rows 2a and 2b on the radii of this circular plate, and defining housings for treatment groups, for example cups 4a and 4b containing samples for analysis, these unit movements having the effect of successively bringing each of these cups to a pre-determined fixed station,

and a distributor denoted as a whole by 3 adapted to be displaced vertically and alternately between a resting position (such as that shown in FIG. 1) and a working position, at the level of the abovesaid fixed station, in which position this distributor is adapted to perform a working or positioning operation. In such an operation, the cups 4a, 4b, placed on the same radius of the circular plate 1, occur at this moment at this fixed station, vertically below the distributor.

To this end, the distributor, which is preferably electro-pneumatically controlled, comprises a jack 6, a

compensating system (not shown) enabling adjustment of the speed of descent of the jack and two parts 7a and 7b participating in the realisation of the abovesaid operation on samples contained in the cups 4a, 4b.

In the particular application envisaged, these parts 7a, 7b constitute elution heads" constituted for example of a plastics material known in commerce under the name of Kel-F they are arranged at the end of the axis of the jack and symetricaliy with respect to the latter, each of these parts having been provided with an axial channel opening into the lower portion, and being provided with a connection 8a or 8b, for example of. the type known under the name of Swagelock, connecting the corresponding axial channel to an elution pump (not shown) through a polyethylene tube 94 or 9b.

When the distributor occurs in its working position, the elution heads 7a, 7b are applied respectively onto the upper portions of the cups 4a, 4b, the abovementioned elution pumps being then in a position to introduce in a manner known in itself of measured quantities of eluant into the cups 4a, 4b through tubes 9a, 9b and elution heads 7a, 7b. In the particular application envisaged the cups such as 4a, 4b borne by the plate are pierced in their bottom, the samples of aminoacids to be subjected to analysis being; then absorbed in a resin. in their working position, the cups 4a, 4b communicate then in a known manner with two hollow parts (not shown) for example of the material called Kel-F" arranged below the circular plate, communicating respectively with the heads of two chromatographic columns (not shown), and machined so that the cups are applied intimately when the elution heads 70, 7b are supported on the upper portions of the cups 4a, 4b.

The successive cups 4a, 4b will then be brought respectively to the fixed station mentioned above by unit angular movements of the plate 1. Each of the concentric rows 20, 2b comprises for example 40 housings 2, so that it will be possible to treat successively forty pairs of samples, by bringing them successively to the work station, by unit rotations of 9 angle.

To this end, the plate 1 comprises radial pegs or tabs 12 respectively corresponding with the aforementioned orifices 2 and the receiver comprises means generally denoted at 13 adapted to coact with that one of the pegs which is in correspondance with the cups 4a, 4b, which then occurs at the aforesaid fixed position, to trigger a unit angular movement of the latter.

in the embodiment illustrated, the means 13 (represented on a large scale in FIGS. 2 to 4) comprise on one hand, a pivoting lever 14 on an axis 16 borne by a part 18 rigidly fixed to the distributor, this pivoting lever comprising a ramp 20 which, in the position of equilibrium of the lever 14 (which position it occupies when the distributor is in its resting position) is vertically over the tab 12 concerned, this ramp 20 being adapted to encounter and to push back this peg on descent of the distributor to its working position, this ramp 20 being however sufficiently short to lose contact with this tab before the plate has undergone the unit displacement on the other hand, a second inclined ramp 22 formed on the part 18, in an, at least in an approximate extension, of the ramp 29, when in the position that the lever 14 occupies at the moment of the abovesaid loss of contact, so as to relay without striking the first in the thrust exerted on the projecting element concerned, so

that the plate can follow and achieve its unit displacement whilst the distributor itself pursues its descent towards its low position the abovesaid pivoting lever 14 being mounted in such a way on the part 18 that, on the reascent of the distributor, it is sufficiently constrained by the following projecting element 12a (FIG. 4) to rock towards a position displaced with respect to its equilibrium position in the direction of unit displacements of the plate; during at least one portion of the return stroke of the distributor to its resting position.

In the embodiment shown in the Figures, the ramp 22 of the-part 18 is substantially in extension of the ramp 20 of the pivoting lever 14, when the latter is in its equilibrium position, for example supported on a stop 24 produced on the part 18. In order not to rock into a displaced position, marked for example by a stop 26, as long as its contact with the tab 12 lasts on descent of the distributor to low position, the major portion (if not the whole) of its ramp 20 is situated, for this position of the lever 14, behind the vertical plane passing through its axis 16 with respect to the displacement direction of the plate.

The end of a unit displacement of the plate is determined in the embodiment described of the apparatus according to the invention, by the coming into abutment of the following projecting element 12a, against a vertical portion of the part 18, which portion is advantageously constituted by a vertical front surface 28 of the part 18, perpendicular to the direction of unit displacements of the plate.

According to another preferred embodiment of the invention, the pivoting lever 14 comprises a front surface 30 facing opposite the direction of the movements of the plate, which occurs substantially in the same vertical plane as the front surface 28, when this lever occurs in its position displaced with respect to its equilibrium position. Under these conditions, the lever 14 is constrained to rock towards its displaced position, especially on reascent of the distributor, under the effect of the action exerted by the tab on its front surface 30, in the course of reascent of the distributor towards its resting position. If necessary, the plate is made to include a simple ball check stop (not shown) mounted on a spring, to avoid any risk of movement of the plate in the reverse direction, under the effect of the interaction of the surface 30 of the lever and of the peg 12a.

Again according to another preferred embodiment of the invention, the part 18 comprises also a rear vertical surface 32, at a distance from the front surface 28 equal, with slight play, to the free space which separates two consecutive projecting elements 12, 12a of the plate. This arrangement is particularly advantageous in that the immobilisation of the plate can be ensured, before the distributor has completely achieved its descending stroke, which achievement results, in the example considered, in the application of the elution heads 7a, 7b onto the cups 4a, 4b occurring at this moment at the aforesaid fixed station.

MODE OF OPERATION The device thus constituted operates then as follows An electric pulse sent to the electropneumatic control device of the jack triggers the descent of the distributor 3; the ramp 20 of the lever 14, initially in its equilibrium position (FIG. 2) contacts the peg 12 which occurs vertically under it and makes it to start to move in the direction of the arrow 14. Owing due to the reduced length of its ramp 20, the lever 14 loses contact with the peg 12 before the plate has reached a unit displacement (FIG. 3), the ramp 22 rigidly fixed to the distributor however relaying the thrust exerted on the peg 12 until the moment when, on one hand, it loses its contact with the peg 12, concerned, and, on the other hand, the following peg 12a comes into abutment against the front surface 28 of the part 18 borne by the distributor (FIG. 4);

The distributor can then complete its travel, its vertical surfaces 28 and 32 sliding between the pegs 12 and 12a, until the moment when its elution heads 7a, 7b are applied onto the cups 4a, 4b. The elution pump is then in the position to produce the elution cycle described in the principal patent. A new pulse sent to the control device of the electropneumatic jack then causes the reascent of the jack, the lever 14 being then constrained by the peg 12a to rock into a displaced position, as shown in FIG. 4, as long as the contact of its front surface 30 with this peg lasts. The lever 14 then comes back into its equilibrium position, especially when the distributor occurs again in its resting position (position represented in mixed line in FIG. 4), so that it is ready to trigger a new unit movement of the plate in the course of the following descent of the distributor, on the encounter of the ramp 20 of the lever 14 with the tab 12a, etc.

The device has the same advantages as the structures envisaged in the abovesaid patent, which advantages will be recalled below more succinctly the control means are of extreme simplicity a single part, the pivoting lever, undertakes as a memory the function that the distributor has to accomplish, in the course of its descent the part 18, by construction, always brings the elution heads (or similar members)into coincidence with the samples, in the absence of any necessary periodical adjustment the distributor does not reach its working position if the plate has not achieved a complete unit movement;

the plate cannot accomplish more than one unit movement, each time that the distributor descends into its working position.

Finally, in the present embodiment, the axis of the lever is not affected in any way by the shocks resulting from abutment of the pegs 12a on one of the portable elements borne by the distributor, each time that the latter arrives at the end of a stroke, which stroke is longer and more controlable.

The stopping of the plate before the arrival of the distributor in its final position is obtained without having recourse to any supplementary part.

As is self-evident and as emerges already from the foregoing, the invention is in no way limited to those of its methods of application, nor to those embodiment of its various parts, which have been more especially indicated; it encompasses, on the contrary, all modifications. For instance, the advancing mechanism according to the invention can be applied advantageously to the stepwise precision advancing of a work support for a plurality of objects in machines, for the manufacture of pills, tablets, electrical components and even large articles in mass-production.

I claim l. A device for bringing a plurality of objects successively to a work station, said device comprising a plate adapted to accommodate the objects in object positions separated by regular spacings, said plate comprising projecting elements at positions corresponding respectively to those of said object positions, said projecting elements being adapted to sustain a thrust capable of moving the plate by one said regular spacing constituting a unit displacement of the plate and a member movable alternately between a rest position and a working position, said member bearing a lever arranged to pivot away from an equilibrium position, said lever comprising a first cam surface adapted to contact and to thrust against one said projecting element at a time to cause a said unit displacement of the plate from one object position to the succeeding object position as the member is moved to its working position, said first cam surface being only of sufficient length for it to lose contact with said projecting element before the plate has completed said unit displacement, the member comprising a second cam surface substantially extending said first cam surface at the moment of said loss of contact, said second cam surface being of sufficient length to complete the unit displacement of the plate when the member completes its movement to its working position, and the pivoting lever being mounted on the member so that it is constrained by the following projecting element of the plate to rock away from said equilibrium position during the time in which the member is returning to its rest position.

2. Device according to claim 1, wherein said first and second cam surfaces are constituted by rectilinear ramps inclined to the horizontal.

3. Device according to claim 1, wherein said plate is circular, is adapted to undergo angular unit movements around its axis, the positions of said object positions being situated on the radii of this plate at equal distances from said axis and said projecting elements being constituted by pegs at the periphery of said plate.

4. Device according to claim 1, wherein the second cam surface substantially extends said first cam surface when the latter is in its equilibrium position, the axis of said pivoting lever being sufficiently displaced in the direction of the movements of the plate with respect to the contact zones of said second cam surface with said projecting elements, for it not to be able to pivot during the whole of this contact.

5. Device according to claim 1, wherein the member is adapted to move vertically alternately between an upper rest position and lower working position.

6. Device according to claim 1, wherein the end of the unit movement of the plate is determined by the coming into abutment against the rear surface of said member, of the projecting element which follows that element which has been pushed back in the course of the movement of the member towards its working position.

7. Device according to claim 6, wherein the major portion of the first cam surface is situated behind the vertical plane of said rear surface.

8. Device according to claim 5, wherein the pivoting lever comprises a front surface which occurs substantially in the same vertical plane as said rear surface when the lever is pivoted away from its equilibrium position.

9. Device according to claim 8, wherein said member is also bounded by a rear vertical surface, said second cam surface extending between said front and rear vertical surfaces and the distance between said two vertical surfaces is equal, with a slight tolerance, to the free space between two consecutive said projecting elements so that the two said vertical surfaces can slide be tween two consecutive said projecting elements in the later portion of the descent of the member to its working position.

i l t i 

1. A device for bringing a plurality of objects successively to a work station, said device comprising a plate adapted to accommodate the objects in object positions separated by regular spacings, said plate comprising projecting elements at positions corresponding respectively to those of said object positions, said projecting elements being adapted to sustain a thrust capable of moving the plate by one said regular spacing constituting a unit displacement of the plate and a member movable alternately between a ''''rest'''' position and a ''''working'''' position, said member bearing a lever arranged to pivot away from an equilibrium position, said lever comprising a first cam surface adapted to contact and to thrust against one said projecting element at a time to cause a said unit displacement of the plate from one object position to the succeeding object position as the member is moved to its working position, said first cam surface being only of sufficient length for it to lose contact with said projecting element before the plate has completed said unit displacement, the member comprising a second cam surface substantially extending said first cam surface at tHe moment of said loss of contact, said second cam surface being of sufficient length to complete the unit displacement of the plate when the member completes its movement to its working position, and the pivoting lever being mounted on the member so that it is constrained by the following projecting element of the plate to rock away from said equilibrium position during the time in which the member is returning to its rest position.
 2. Device according to claim 1, wherein said first and second cam surfaces are constituted by rectilinear ramps inclined to the horizontal.
 3. Device according to claim 1, wherein said plate is circular, is adapted to undergo angular unit movements around its axis, the positions of said object positions being situated on the radii of this plate at equal distances from said axis and said projecting elements being constituted by pegs at the periphery of said plate.
 4. Device according to claim 1, wherein the second cam surface substantially extends said first cam surface when the latter is in its equilibrium position, the axis of said pivoting lever being sufficiently displaced in the direction of the movements of the plate with respect to the contact zones of said second cam surface with said projecting elements, for it not to be able to pivot during the whole of this contact.
 5. Device according to claim 1, wherein the member is adapted to move vertically alternately between an upper rest position and lower working position.
 6. Device according to claim 1, wherein the end of the unit movement of the plate is determined by the coming into abutment against the rear surface of said member, of the projecting element which follows that element which has been pushed back in the course of the movement of the member towards its working position.
 7. Device according to claim 6, wherein the major portion of the first cam surface is situated behind the vertical plane of said rear surface.
 8. Device according to claim 5, wherein the pivoting lever comprises a front surface which occurs substantially in the same vertical plane as said rear surface when the lever is pivoted away from its equilibrium position.
 9. Device according to claim 8, wherein said member is also bounded by a rear vertical surface, said second cam surface extending between said front and rear vertical surfaces and the distance between said two vertical surfaces is equal, with a slight tolerance, to the free space between two consecutive said projecting elements so that the two said vertical surfaces can slide between two consecutive said projecting elements in the later portion of the descent of the member to its working position. 